In, for instance, a pay television broadcasting system(or a music/audio program broadcasting system) by way of a broadcasting satellite, programs are often scrambled, or encoded, for broadcast so as to prevent these programs from being illegally intercepted by unauthorized parties. A person who wishes to become an authorized viewer/listener, or contractor(subscriber), of such a pay television program typically must contract with a programming service provider for such service. Upon contracting for service, the subscriber typically receives a scramble key (decrypt key) or code, so that he/she may descramble the scrambled program to legally listen to the pay TV program.
Nowadays, so-called "COATEC" system and the "SKYPORT" system have been practically utilized as a scramble system in pay television broadcasting via broadcasting satellites.
Recently, as a data broadcasting system for electronically distributing data such as newspaper (news data or newspaper data), such a broadcasting system has been proposed that newspaper data is inserted into a satellite data channel, and the resultant data is transmitted through the broadcasting satellite. In this case, for instance, at a data receiving apparatus installed in a contractor's (subscriber's)home/reception location who has made the newspaper data distribution contract with the newspaper data supplied, a signal transmitted through a satellite is received to derive the newspaper data inserted into the data channel. Then, this newspaper data is recorded on such a recording medium as a magnetic disk and a magneto optical disk, and is read out therefrom if necessary. The read newspaper data is represented on, for instance, a display unit, or printed out, so that the contractor can read the newspaper.
In other words, according to the above-described scramble system, since the programs are transmitted by only selecting one of the two transmission data processing methods, namely by scrambling the program data or by processing the program data in the non-scramble manner, merely uniform program service may be provided so that all of the contractors can observe the specific newspaper data and is not possible that some contractors cannot observe this specific newspaper data.
Currently existing services provide subscribers with textual news data via computer network. Such information is typically provided to the subscribers regardless of the subscribers' interest or desire in receiving all types of news data. In other words, when subscribers subscribe to such a news service they receive, or have access to, all news data of all types or categories, regardless of their desire to receive or not receive certain news data. In essence, the subscriber typically pays for more news data than they actually use or receive. As a result, all of the contractors must pay their service fees regardless of whether or not they actually observe the broadcasted newspaper data. Accordingly, in the view of the contractors, they must pay not only the service fees for the necessary newspaper data, but also the service fees for the unnecessary newspaper data, so that they may feel an unfair fee payment system. This unfair fee payment system could impede promotion of the program contract, and furthermore could lower the profit of the information suppliers.
In the above-described scramble system, a scramble key is required to decrypt the scrambled program when the scrambled program is received. As a consequence, for instance, if the newspaper data (namely, scrambled newspaper data) have been received prior to the establishment of a contract are recorded on the recording medium, after the establishment of the contract, even if the contractor may have his own scramble key, he cannot decrypt the scrambled newspaper data which have been recorded on this recording medium.